More details on VIta’s Memory

Speaking in answer to Kotaku Japan (via Andriasang) the hardware giant revealed games that save internally do not give you the option to save to a separate Memory Card. In other words, only games which require a memory card will save to one, while games which save to their own game card will not, presumably meaning that you will not be able to store these saves anywhere else (not confirmed).

Its also been revealed that when a game says it requires a memory card then you will need to insert one into the system before the game will start. Generally, games that require a memory card do so for future expansion or patches, so it looks like buying one along with your system may be essential.